Facing structure for a stair step forward portion

ABSTRACT

A facing structure for a forward portion of steps of the stair comprises a working member made of a resilient material, a horizontal and a vertical fastening members connected to rearward and lower surfaces of the said working member. The thickness H of the working member and the modulus of elasticity E of a resilient material satisfy the relationships: H&gt;h+h 1 , E H×k, where: h—the thickness of a facing material of the horizontal surface of stair steps [m], h 1 —the thickness of the horizontal fastening member [m], k=10 11  [n/m 3 ].

CROSS-REFERENCED TO RELATED APPLICATION

The present application is a Continuation Application of U.S. application Ser. No. 09/230,439 filed Feb. 9, 1999, which is incorporated herein by reference and which is a national phase of PCT/RU98/00192 filed Jun. 15, 1998, which claims priority from RU 97110010 filed Jun. 16, 1997.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to the field of construction and, more particularly, to the structures of edges of faced stair steps.

2. Description of the Prior Art

An example of a facing structure for a stair step forward portion is described in DE Patent No. 3.907,959; Int. C1. E04F 11/16, issued 1990. In this disclosed art, said facing structure comprises a F-shaped working member and a vertical anchor portion connected to a lower surface of the said working member. In so doing, both the working member and anchor portion are made of a resilient material.

To secure the known facing structure, the use is made of an additional fastening member fabricated in the form of a metal angle having a longitudinal slot in which the vertical anchor portion of a removable facing structure of the stair step forward portion is located. Moreover, it is necessary that horizontal facing plates of stair steps be provided with a special platform to accommodate the working member of the said facing structure for the stair step forward portion. Thus, the assembly of the known facing structure for the stair step forward portion is rather labor-consuming.

The drawbacks with this known facing structure for the stair step forward portion reside also in the fact that due to a small thickness of the working member, it is essentially impossible to ensure both a long operation life of the facing structure and conditions of spontaneous decomposition of the ice coating formed on the surface thereof under the action of a pedestrian weight. Besides, the availability of only one vertical fastening member fails to provide a reliable securing of the facing structure.

Another example of a facing structure for a stair step forward portion is described in FR Patent No. 2,694,585; Int. C1. E04F 11/16, issued 1994, being the closest prior art with respect to the totality of accomplished operations and structural features in accordance with the present invention. In this disclosed art, said facing structure comprises a Γ-shaped working member, a horizontal and a vertical fastening members all made of a resilient material, said fastening members are interconnected and attached to the working member of the facing structure through an additional connecting member.

A disadvantage of the known facing structure for the stair step forward portion resides in the fact that it has a complicated cross-section shape necessitating the use of complex attachments when fabricating thereof. Moreover, it is necessary that horizontal facing plates of stair steps be provided with a special platform to accommodate the working member of the said facing structure for the stair step forward portion, in other words, a strictly defined thickness which complicates the assembly of the facing structure and increases the cost of works performed.

Another disadvantage of the known facing structure for the stair step forward portion consists in that due to a small thickness of the working member, it is essentially impossible to ensure both a long operation life of the facing structure and conditions of spontaneous decomposition of the ice coating formed on the surface thereof under the action of a pedestrian weight.

SUMMARY OF THE INVENTION

It is, therefore, an object of the present invention to provide a facing structure for a stair step forward portion having a working member whose structural accomplishment would enable to achieve not only simplification in the processes of the facing structure manufacture and assembly and hence a decrease in the cost of civil-engineering, but also the increase in the operational parameters at the expense of the provision of both a long operation life and the amount of the “ice—working member” interface stress concentration required to decompose the ice under the action of a pedestrian weight.

This object is solved in a facing structure for a stair step forward portion in accordance with the present invention, comprising a working member made of a resilient material and a horizontal and a vertical fastening member, wherein the working member is manufactured in the form of a beam with its rearward and lower surfaces being connected to said horizontal and vertical fastening members respectively, the thickness H of the working member and the modulus of elasticity E of a resilient material satisfy the relationships: H>h+h ₁,   (1) E≦H×k,   (2) where:

h—the thickness of the facing material of the horizontal surface of stair steps [m],

h₁—the thickness of the horizontal fastening member [m],

k—a constant equal to 10¹¹ [N/m³].

It is advisable that fastening members be made of the material of the working member and located, for example, integral therewith.

It is advantageous that the fastening members be made of the material whose modulus of elasticity is at least by an order of magnitude greater then the modulus of elasticity of a resilient material of the working member.

Such an accomplishment of the facing structure of the stair step forward portion enables simplification of the process of its manufacture, since connecting members are absent and fastening members are connected not to each other but to a rather massive working member of the facing structure. Besides, the use of the facing structure of the stair step forward portion in accordance with the present invention makes it possible to simplify the process of its assembly, since it is unnecessary to provide the facing material of stair step surfaces with special platforms. In other words, conventional plates of rectangular shape having the same thickness may be used without any special additional working-up of their forward portions.

A further result attained when using the facing structure in accordance with the present invention consists in that by satisfying the above relationships (1) and (2), the edges of the stair steps acquire springiness. As a consequence, stresses arise on the “working member—ice coating” interface whose amount meets the conditions of the “effect of self-cleaning” of the edges of outdoor stair steps from the ice (ice coating) under the action of a pedestrian weight.

BRIEF DESCRIPTION OF THE DRAWINGS

The various objects, advantages and novel features of the present invention will be more readily apparent from the following detailed description when read in conjunction with the appended drawings, in which:

FIG. 1 is a general cross-sectional view of faced stair steps, in accordance with the present invention;

FIG. 2 is a side view of an embodiment of fastening members of a facing structure of a stair step forward portion, said members being made of a resilient material and integral with a working member, in accordance with the present invention;

FIG. 3 is a side view of an embodiment of metal fastening members of a facing structure of a stair step forward portion, in accordance with the present invention.

BEST MODE TO CARRY OUT THE INVENTION

Referring to FIG. 1, a facing structure for a forward portion of steps of the stair 1 comprises a working member 2 made in the form of a beam, a vertical fastening member 3 and a horizontal fastening member 4, with lower 5 and rearward 6 surfaces of the said working member 2 being connected to said vertical 3 and horizontal 4 fastening members respectively.

In the preferred embodiment of the present invention, an upper surface of the working member 2 is provided with teeth 7. The horizontal fastening member 4 is located under a facing material 8 of the surface of a respective step of the stair 1. The vertical fastening member 3 is located under a facing material 9 of the surface of a respective riser of the stair 1. Ceramic, marble and the like plates may be used as the facing material 8 and 9. Attachment of the facing structure of the stair step forward portion to a concrete stair 1 and of the facing material 8 and 9 is accomplished by means of an adhesive 10. In the preferred embodiment of the present invention, a cold-resistant “Atlas Plus” brand adhesive is used.

Referring again to FIG. 1, it is advisable that the horizontal fastening member 4 be mounted flush with the lower surface 5 of the working member 2, since in this case the process of assembly is simplified.

Referring to FIGS. 1 and 2, the fastening members 3 and 4 may be made of the same material as that of the working member 2, and in particular integral therewith. However in some cases, it is advisable that the fastening members 3 and 4 be made of more rigid material (FIG. 3), for example aluminum alloy.

To ensure the “effect of self-cleaning” from the ice and ice coating, the thickness H and the modulus of elasticity E of the material of the working member 2 must satisfy the relationships (1) and (2).

Referring to FIG. 2, additional ductility of the working member 2 is achieved by providing holes 11 through the length of the working member. The holes may have round, square or triangular cross-sections, and the dimensions of the hole are selected based on the required ductility.

If the fastening members 3 and 4 are made of more rigid material (whose modulus of elasticity is at least by an order of magnitude greater then the modulus of elasticity of a resilient material of the working member 2), they may have different section, for example an angle F-shaped section (FIG. 3).

Assembly of the facing structure of the stair step forward portion is carried out in the following sequence. The surface of the stair step and riser cleaned from dirt and dust is coated with the layer of an adhesive 10. Thereupon, the facing structure of the rearward stair step portion is mounted. Then an upper surface of the horizontal fastening member 4 and a rearward surface 6 of the working member 2 are coated with the layer of an adhesive 10 followed by the installation of a plate 8 of the facing material of the horizontal step surfaces. The facing of a riser using a facing material 9 is carried out in much the same way. Since the thickness H of the working member 2 exceeds the sum of the thickness h of the facing material 8 and the thickness h₁ of the horizontal fastening member 4, then, by varying the layer thickness of the adhesive 10, a required location of the facing members, for example flush-mounted, is provided. Connection of the working member 2 and fastening members 3 and 4 of the facing structure of the stair step forward portion directly to the stair 1 imparts more reliability and longevity to the structure.

While the structure is in use, the ice or ice coating is formed on the surface of the working member 2. Under the action of a pedestrian weight, elastic strains of the working member 2 take place resulting in stresses on the “working member—ice” interface, the amount of said stresses being sufficient to decompose the ice coating. In this way “self-cleaning” of the most dangerous portion of the stair step from the ice occurs.

INDUSTRIAL APPLICABILITY

The facing of the stair step forward portion may be used when manufacturing outdoor stairs and that for pedestrian underpasses thus ensuring simplification of the structure and assembly and realizing the “effect of self-cleaning” from the ice (ice coating) while it is in use.

Although the present invention has been described with reference to preferred embodiments, the invention is not limited to the details thereof, and various changes and modifications obvious to one skilled in the art to which the invention pertains are deemed to be within the spirit, scope and contemplation of the invention as further defined in the appended claims. 

1. A self-cleaning facing structure adapted to be fixed to an outdoor stair step, said facing structure comprising: a beam-like working member made of a resilient material and having an exposed treading surface adapted to be tread upon by pedestrians: a horizontal fastening member projecting from a rearward facing surface of the working member; and a vertical fastening member projecting from a downward facing surface of the working member; wherein the horizontal and vertical fastening members are integrally formed with the beam-like working member as a single unit; wherein the horizontal fastening member is adapted to be mounted on a horizontal tread surface of the step, and the vertical fastening member is adapted to be mounted on a vertical tread surface of the step; wherein the horizontal fastening member is adapted to have a horizontal facing material applied thereon, and the vertical fastening member is adapted to have a vertical facing material applied thereon; and wherein a modulus of elasticity E of the resilient material of the working member and a thickness H of the working member satisfy E/H−k, where k is a constant having a value of 1011 Newtons per cubic meter.
 2. The facing structure of claim 1, wherein a lower surface of the horizontal fastening member is formed to be flush with a lower surface of the working member.
 3. The facing structure of claim 1, wherein the horizontal and vertical fastening members are made of the same resilient material as the working member.
 4. The facing structure of claim I, wherein the horizontal and vertical fastening members are made of a material whose modulus of elasticity is at least an order of magnitude greater than the modulus of elasticity E of the resilient material of the working member.
 5. An outdoor stair step assembly comprising: (i) an outdoor stair step having a horizontal tread surface and a vertical tread surface; and (ii) a self-cleaning facing structure fixed to the outdoor stair step, wherein said facing structure comprises: an exposed beam-like working member made of a resilient material; a horizontal fastening member projecting from a rearward facing surface of the working member and mounted on the horizontal tread surface of the outdoor stair step; and a vertical fastening member projecting from a downward facing surface of the working member and mounted on the vertical tread surface of the outdoor stair step; wherein the horizontal and vertical fastening members are integrally formed with the beam-like working member as a single unit; (iii) a horizontal facing material mounted on the horizontal fastening member; and (iv) a vertical facing material mounted on the vertical fastening member; wherein a modulus of elasticity F of the resilient material of the working member and a thickness H of the working member satisfy E/H=k, where k is a constant having a value of 1011 Newtons per cubic meter.
 6. The outdoor stair step assembly of claim 5, wherein a lower surface of the horizontal fastening member is formed to be flush with a lower surface of the working member.
 7. The outdoor stair step assembly of claim 5, wherein the horizontal and vertical fastening members are made of the same resilient material as the working member.
 8. The outdoor stair step assembly of claim 5, wherein the horizontal and vertical fastening members are made of a material whose modulus of elasticity is at least an order of magnitude greater than the modulus of elasticity E of the resilient material of the working member.
 9. The outdoor stair step assembly of claim 5, wherein the horizontal and vertical fastening members are made of an aluminum alloy.
 10. The outdoor stair step assembly of claim 5, wherein holes are provided through the working member.
 11. The outdoor stair step assembly of claim 10, wherein the holes have round, square or triangular cross-sections.
 12. The outdoor stair step assembly of claim 5, wherein corrugations are formed on the treading surface of the working member.
 13. The outdoor stair step assembly of claim 5, wherein the thickness H of the working member is greater than the sum of a thickness h1 of the horizontal fastening member and a thickness h of the horizontal facing material to be applied to the horizontal fastening member. 